Appeal 20260

5703.1.1 Classified Locations for Flammable Liquids

Areas where flammable liquids are stored, handled, dispensed or mixed shall be in accordance with Table 5703.1.1

NOTE ADDED FOR RECONSIDERATION
Appeal 20135 (a reconsideration of appeal 18560) was granted on March 20th, 2019 and is copied here in its entirety. Any additional text added for the current reconsideration will be clearly indicated. The appeal makes reference to a requirement on pg 26 of the Analysis Report ( attached ) submitted by BEA Consultants LLC, stating “Ventilation systems shall be connected to emergency power, so that the ventilation system will still operated for 90 minutes in the event of normal power failure.” This is no longer required by the city of Portland for this use and occupancy but may have been at the time the report was prepared ( October 17, 2017). As it is no longer a requirement of the code, we are removing it from the text of this appeal for your reconsideration. Additionally, the EOR will amend the submitted report to indicate it is not a requirement

Appeal 18560 was denied October 17, 2018. It upheld the plans examiners requirement that electrical equipment in the post-processing area meet the requirements of a class 1, division 2 location.

We request that appeal ID 18560 be reconsidered and the alternative protection technique provided by the ventilation system be allowed. The appeal reconsideration also removes item 2 contained in the original appeal.

Proposed Design
Co2 Dynamics has (2) Eden CO2 extractors and will have a new state of the art exhaust system, and a gas detection system for both CO2 and ethanol that will be connected to emergency power. Ethanol detection will be by a Honeywell Sensepoint XCD gas detector (or equal) set to 1000 ppm. Exhaust fans will be installed providing continuous 900 CFM (1 CFM per SF) air flow and 2700 CFM (3 CFM per SF) if and when alarms are activated. Audible alarms and strobes, interconnected with the detectors, will also be installed. The entire space will be under negative pressure, either under normal operation (1 CFM per SF) or when gas detection system alarms are activated (3CFM per SF), so any heavier than air evaporative ethanol vapor is designed to be contained and exhausted via the low wall exhausts through a spark resistant rooftop exhaust fan system. NOTE ADDED FOR RECONSIDERATION The sensors, alarms and controls of the exhaust system will be connected to emergency power so they will still operate for 90 minutes in the even of a normal power failure. The building is fully sprinkled and has a maximum travel distance of 52 feet.

500.7.L of the 2017 OESC states that “other protection techniques used in equipment identified for use in hazardous (classified) locations...shall be acceptable protection…” Please refer to the attached Ventilation Requirement Report from BEA consulting engineers showing the ventilation rate to be well in excess of minimum requirements considering a worst case spill ( 3 liters total in use) and using a factor of safety of 5.

Section 5703.1.1 of the Oregon Fire Code allows that ...“ The extent of the classified area is allowed to be reduced, or eliminated, where sufficient technical justification is provided to the fire code official that a concentration in the area in excess of 25 percent of the lower flammable limit (LFL) cannot be generated.”

Ethanol has an LFL of 3.3% in air at room temperature. This corresponds to 33,000 ppm and so 25% of the LFL of Ethanol is 8,250 ppm. The TLV (Threshold Value Limit) for ethanol is 1000 ppm, set by various safety agencies. OSHA has a PEL (Permissible Exposure Limit) of 1000 ppm.

CO2 will install an ethanol gas sensor (see above), which will trigger emergency ventilation in the event that ethanol levels exceed 1000 ppm. The calculated air changes per hour will be 22 ½ , or one air change approximately every 2 ½ minutes. This system will ensure a maximum air saturation of less than 1/8th of the 25% LFL threshold set in the code.

Additionally, consider that NFPA 497 says the following about unclassified locations:

5.5.1 Experience has shown that the release of ignitable mixtures from some operations and apparatus is so infrequent that area classification is not necessary. For example, it is not usually necessary to classify the following locations where combustible materials are processed, stored or handled:
Locations that have adequate ventilation, where combustible materials are contained within suitable, well-maintained, closed piping systems
Locations that lack adequate ventilation, but where piping systems are without valves, fittings, flanges, and similar accessories that may be prone to leaks
Locations where combustible materials are stored in suitable containers
Locations where the use of combustible liquids, or flammable liquids or gasses, will not produce gas or vapor sufficient to reach 25 percent of the lower flammable limit (LFL) of that combustible material

Lastly, see the attached UL Certificate of compliance showing the rotary evaporators’ compliance with safety standards for such equipment, which do not include requirements for Class 1, Division 2 wiring.